Description

Source is a Rotel RCC-1055 "CD MULTIDISC CHANGER" HDCD (2003). For some reason, the System Builder won't load it. It's my latest update, so I'll get to it in a bit. :)

After receiving some legacy gear, which included the power amps and a Lexicon DC-1 Digital Control Center, I have done some low-level, low-cost experimenting. Even though it was a better music system than I'd ever had (I'd never *really* had one), I was having trouble. The DC-1 could be configured to sound great for some things, but I never found an acceptable universal setting. At this time, my source was a Sony BDP-S360 BluRay player, and the system doubled as a two-channel av, including Cox Cable. When our cheap projector died, I prevailed upon my wife to perhaps take a hiatus on the av solution. We cancelled cable and moved the BluRay player to the computer in our bedroom. Netflix, DVD's, etc. all through a 24" HD-compatible monitor. Sure, it's a dorm-level solution, but it suits us for now. What was once our main entertainment area suddenly was freed up for two-channel dedication. I briefly used an old Panasonic DVD player as my source. It was old, stored for years, and began skipping a few weeks into use. Probably could have saved it, but I was eager to be rid of it anyway. In my haste, I took what pocket cash I had to the pawn shop around the corner and picked up the more-or-less "current" basic Sony cd changer. I had not yet given up on the DC-1.

Not too long later, a passive preamp showed up on Craigslist. I'd been paying attention to Craigslist long enough to know that this was unusual. I didn't care about the brand--at 50.00, I considered it worth the risk. I was already intrigued by the passive preamp notion, which I think is a natural curiosity for a non-technical person: the simplicity makes it seem easier to grasp and appeals to the logical purist in all of us. Performance was a big question mark, as I had no experience with passives in the least. It turned out to be a PS Audio "PS VK Control Center, and very little info is available online. But how much can be said about such a simple device? I'm sure is was an oddity in 1981 and considered by many to be unworthy of review. I imagine many would have thought it equivalent to reviewing a light switch. Anyway, that's my impression. PS Audio's website reports that it was not well received.

I disconnected the Lexicon and put the VK in its place. I was immediately impressed by the lack of "sizzle." I also, however, sensed the roll-off issue often reported in discussions and tutorials about passives. Looking into this a little, my poor non-technical brain was able to grasp some simple instructions regarding impedance matching/bridging when using a passive pre. Apparently, the roll-off issue is rooted in impedance, and the most important figures to note are your source's output impedance and amplifier's input sensitivity. A couple of sources indicated that an amp's input sensitivity, expressed in ohms, should be at least 10 times the output sensitivity of the source. Well, this Sony cd changer's output impedance was listed at 10 kOhms (up to 50 kOhms), and the input sensitivity of my amps is 33 kOhms. I couldn't ignore the mismatch.

I hemmed and hawed over whether to replace the cd source or just get a dac. I decided that when I would get a dac, it would be a real investment. If I could find a used one for 300.00 that I liked, I would have moved on it. As it turned, out Stereo Design in San Diego had a used Rotel cd changer (I know, changers aren't "audiophile"--I like it anyway), output impedance of 75 ohms. Now that I have a decent source matched well with the amps, the system seems to have clicked.

It all comes out the speakers. I found these Sony SS M3's on Craigslist for a song. Although little is available online, all user reviews are positive. The flagship of this series, the ES SS-M9, was lauded by Stereophile. Anyway, I am quite fond of them. Although I miss low end--these use a 4th order crossover bass reflex with a 6.5" woofer only rated down to 70 Hz--I nevertheless enjoy what I hear. Near field two-way bookshelf listening is plenty of fun. They are biamped using two Rotel RB980BX stereo amps (120 wpc). Way more power on tap than I need. I don't know the engineering principles, but my sense is that the over-amplification helps my passive pre solution perform. I'm guessing the amps are operating Type A most of the time, but I'm still stymied by the whole A/B amplification topic.

I'm always interested in feedback. I'm chilling out for awhile to enjoy the music. I will probably work on finishing this solution before adding more sources. So, power conditioning, as yet unaddressed, is on my radar. I also need some speaker stands. I had them on the floor. Right now they're on dining chairs, the fabric of which is helping to isolate them surprisingly well. My wife is unenthusiastic about this development. I also need a rack for my components, which are currently stacked on an old steamer trunk partially filled with old clothes. I have little doubt that this object colors the sound worse than any other room factor, more because of sound bouncing off of the hollowish object rather than component vibration. components. Following proper room treatment, I'm expecting the sound stage to open up and relax a bit. Currently, I feel that the speakers "disappear" impressively up to medium-high volumes. I think this will improve slightly, and I believe the bottom end roll-off will sweeten. As it is, the move to a passive pre improved the bottom-end roll-off tremendously.
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Components Toggle details

    • PS Audio PS VK Control Center
    Passive Preamp. This unit dated 11/81.
    • Rotel RB-980bx
    120 wpc ss stereo amp. I have two of these in a vertical (passive) biamp.
    • Sony SS-M3
    2-way, biampable, cherry veneer. 20kHz-70hz. 1998
    • Monster Monster Ultra High Performance Audi
    I admit it. For cables, I walked into Fry's and just sort of winged it. I have two of these on the PS VK outputs.
    • Matix Ultra Pure Directional Acoustic
    .5m lengths on all three sets: 1)cd analog out to preamp, 2) connected to left channel y-adapter between preamp and amp number one, 3) connected to right channel y-adapter between preamp and amp number two.
    • Vertical Audio Cable E312655
    14 awg, 4 cond, 41 stranded oxygen free. In-Wall cable provided by a friend who does av installation. 2m lengths. Four cables housed, each of which used for biwiring.

Comments 4

222222&text=po
Owner
Oooh, Eldragon, there were four of them for sale on Ebay just a couple of weeks ago. If you set up an Ebay reminder, you'll get notified whenever your item comes up. I also saw a pair of M9's locally on CL about two months ago. So, they do come up. Just have to be patient and pounce when the time comes.

I'll have to update the system specs soon with pics. I've since put the speakers on Mapleshade stands and placed the rest of the components on an actual audio rack. Interconnects have all been replaced with Blue Jeans Cable. I'm less embarrassed now about showing it. It's still modest, but at least it's put together, and I really enjoy the sound. I also have a Rotel RC980BX preamp arriving tomorrow. I'll be very interested to see how it compares to the passive preamp.

I've come back around to thinking about active biamping. My next project will likely involve taking measurements, etc. so that I can have some line level crossovers made. I'm looking at the basic passive XM46SB units by Marchand (250.00 each). Part of the reason I'm playing with a more conventional preamp is so I can possibly use it with passive line level crossovers, since a passive pre plus passive crossovers would likely have problems in my system. I'll need at least a few months before taking active biamp step.

poprhetor

222222&text=el
Yes, that's one cool system. I am currently looking for Sony SS M3 on Asylum. Reviews are great for that line of speakers.

eldragon

Center
Cool system and story. I have shopped Craigslist as well.

coolkane

222222&text=po
Owner
On second glance, I should have edited more. Oh well, nothing tragic. :)

poprhetor

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